Amendment to IET Wiring Regulations - Are you compliant?

01/07/2015

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As the latest amends to the IET Wiring Regulations come into effect, Steve Marr – an expert in power distribution at Legrand, calls on designers to make sure they are aware of the changes and to ensure they comply.

Under Chapter 41 of ‘Amendment 3’ to BS 7671:2008, which comes into effect on 1st July 2015, a documented risk assessment must now be undertaken in order for non-domestic socket outlets with a rated current below 20A to be installed, without an residual current device (RCD1) to protect it.

The latest amendment reinforces the requirement for RCDs in non-domestic environments, making it harder for designers to omit the use of RCDs from installations. From 1st July, the designer must produce a risk assessment highlighting if RCD protection is unnecessary in an application and to justify the reasoning for this decision. If an incident occurs, as a result of the omission of RCD protection, the risk assessment could be used in a court of law.

Until now, the practice of omitting RCD protection on some sockets has put health and safety at risk, partly as a result of some ambiguous terminology that stated RCDs could be omitted if the socket outlet was to be used ‘under the supervision of skilled or instructed persons’. Unfortunately, this ambiguity led to the installation of socket outlets without residual current protection. One such example was in a school where the sockets were to be used ‘under the supervision of a person instructed by the head teacher’.

Needless to say, the unnecessary risk that this poses clearly highlights the need for change – ensuring safety as paramount. Unfortunately, while the cost of RCDs and ‘nuisance tripping’ have influenced the purchase and installation of these protective devices to date, it shouldn’t be at the detriment of safety within the workplace.

While ‘nuisance tripping’ can be an inconvenience, it often stems from having too much electrical equipment supported by one RCD. Good design should see socket outlets connected to an RCD that serves a small number of sockets or equipment - ensuring that the earth leakage is kept within tolerance and therefore unwanted tripping is avoided.

In short, the potential consequences of not designing and installing RCDs, far outweighs the initial upfront cost and potential trip risk. The new amendment is a welcome addition, enforcing the requirement for RCDs in all non-domestic applications. With a greater emphasis on a detailed risk assessment, and with responsibility falling on to designers, electrical safety can be greater assured. Awareness of the changes amongst designers must now be a priority.

1 An RCD can be omitted for specifically labelled or otherwise suitable identified socket outlets for connection of a particular item of equipment. See BS 7671: 2008+A3:2015 Chapter 41.1.3.3 for more details.